fix: improve config diagnostic delivery

7 files changed, 143 insertions, 55 deletions

diff --git a/src/app/mod.rs b/src/app/mod.rs
index 51bdd33e..99181361 100644
--- a/src/app/mod.rs
+++ b/src/app/mod.rs
@@ -1338,16 +1338,8 @@ impl App {
             // On `min > max`, treat the entire `[ui]` section as invalid: keep
             // the previous settings and skip the section so the re-clamp below
             // — and every subsequent render/drag — can never panic.
-            if crate::config::validated_sidebar_bounds(
-                config.ui.sidebar_min_width,
-                config.ui.sidebar_max_width,
-            )
-            .is_none()
-            {
-                diagnostics.push(format!(
-                    "ui.sidebar_min_width ({}) is greater than sidebar_max_width ({}); keeping previous [ui] settings",
-                    config.ui.sidebar_min_width, config.ui.sidebar_max_width,
-                ));
+            if let Some(diagnostic) = config.invalid_sidebar_bounds_diagnostic() {
+                diagnostics.push(format!("{diagnostic}; keeping previous [ui] settings"));
             } else {
                 diagnostics.extend(config.ui.sound.diagnostics());
 
@@ -2786,21 +2778,21 @@ mod tests {
 
         let report = app.reload_config();
         assert_eq!(report.status, crate::config::ConfigReloadStatus::Partial);
+        assert!(report.diagnostics.iter().any(|diagnostic| {
+            diagnostic.contains("sidebar_min_width")
+                && diagnostic.contains("sidebar_max_width")
+                && diagnostic.contains("greater")
+        }));
         assert_eq!(app.state.sidebar_min_width, original_min);
         assert_eq!(app.state.sidebar_max_width, original_max);
         assert_eq!(
             app.state.mouse_capture, original_mouse_capture,
             "[ui] is treated as invalid on bad bounds; mouse_capture must not apply"
         );
-        assert!(app
-            .state
-            .config_diagnostic
-            .as_deref()
-            .is_some_and(|message| {
-                message.contains("sidebar_min_width")
-                    && message.contains("sidebar_max_width")
-                    && message.contains("greater")
-            }));
+        assert_eq!(
+            app.state.config_diagnostic.as_deref(),
+            Some("config.toml; herdr config check")
+        );
 
         std::env::remove_var(crate::config::CONFIG_PATH_ENV_VAR);
         let _ = std::fs::remove_dir_all(path.parent().unwrap());
@@ -2823,6 +2815,9 @@ mod tests {
         let report = app.reload_config();
 
         assert_eq!(report.status, crate::config::ConfigReloadStatus::Partial);
+        assert!(report.diagnostics.iter().any(|diagnostic| {
+            diagnostic.contains("keys.new_workspace") && diagnostic.contains("disabling binding")
+        }));
         assert_eq!(
             (app.state.prefix_code, app.state.prefix_mods),
             original_prefix
@@ -2832,14 +2827,6 @@ mod tests {
             app.state.toast_config.delivery,
             crate::config::ToastDelivery::Terminal
         );
-        assert!(app
-            .state
-            .config_diagnostic
-            .as_deref()
-            .is_some_and(|message| {
-                message.contains("keys.new_workspace") && message.contains("disabling binding")
-            }));
-
         std::env::remove_var(crate::config::CONFIG_PATH_ENV_VAR);
         let _ = std::fs::remove_dir_all(path.parent().unwrap());
     }
@@ -2891,6 +2878,10 @@ mod tests {
         let report = app.reload_config();
 
         assert_eq!(report.status, crate::config::ConfigReloadStatus::Partial);
+        assert!(report
+            .diagnostics
+            .iter()
+            .any(|diagnostic| diagnostic.contains("invalid ui config")));
         assert!(app
             .state
             .keybinds
@@ -2900,12 +2891,6 @@ mod tests {
             app.state.toast_config.delivery,
             crate::config::ToastDelivery::Herdr
         );
-        assert!(app
-            .state
-            .config_diagnostic
-            .as_deref()
-            .is_some_and(|message| message.contains("invalid ui config")));
-
         std::env::remove_var(crate::config::CONFIG_PATH_ENV_VAR);
         let _ = std::fs::remove_dir_all(path.parent().unwrap());
     }
@@ -2929,6 +2914,10 @@ mod tests {
         let report = app.reload_config();
 
         assert_eq!(report.status, crate::config::ConfigReloadStatus::Partial);
+        assert!(report
+            .diagnostics
+            .iter()
+            .any(|diagnostic| diagnostic.contains("invalid terminal config")));
         assert_eq!(app.state.default_shell, original_default_shell);
         assert_eq!(app.state.shell_mode, original_shell_mode);
         assert_eq!(app.state.new_terminal_cwd, original_new_cwd);
@@ -2936,12 +2925,6 @@ mod tests {
             app.state.toast_config.delivery,
             crate::config::ToastDelivery::Terminal
         );
-        assert!(app
-            .state
-            .config_diagnostic
-            .as_deref()
-            .is_some_and(|message| message.contains("invalid terminal config")));
-
         std::env::remove_var(crate::config::CONFIG_PATH_ENV_VAR);
         let _ = std::fs::remove_dir_all(path.parent().unwrap());
     }
@@ -3047,7 +3030,7 @@ mod tests {
             .config_diagnostic
             .as_deref()
             .is_some_and(|message| {
-                message.contains("config parse error") && message.contains("keeping current config")
+                message.contains("config.toml:1:6") && message.contains("herdr config check")
             }));
         assert!(app.state.toast.is_none());
 
diff --git a/src/cli.rs b/src/cli.rs
index 58bd3a54..494ed14e 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -224,6 +224,7 @@ fn run_config_command(args: &[String]) -> std::io::Result<i32> {
     };
 
     match subcommand {
+        "check" => config_check(&args[1..]),
         "reset-keys" => config_reset_keys(&args[1..]),
         "help" | "--help" | "-h" => {
             print_config_help();
@@ -236,6 +237,32 @@ fn run_config_command(args: &[String]) -> std::io::Result<i32> {
     }
 }
 
+fn config_check(args: &[String]) -> std::io::Result<i32> {
+    match args {
+        [] => {}
+        [flag] if matches!(flag.as_str(), "help" | "--help" | "-h") => {
+            eprintln!("usage: herdr config check");
+            return Ok(0);
+        }
+        _ => {
+            eprintln!("usage: herdr config check");
+            return Ok(2);
+        }
+    }
+
+    let diagnostics = crate::config::Config::load().diagnostics;
+    if diagnostics.is_empty() {
+        println!("config: ok");
+    } else {
+        println!("config: issues found");
+        for diagnostic in &diagnostics {
+            println!("{diagnostic}");
+        }
+    }
+
+    Ok(i32::from(!diagnostics.is_empty()))
+}
+
 fn config_reset_keys(args: &[String]) -> std::io::Result<i32> {
     if !args.is_empty() {
         eprintln!("usage: herdr config reset-keys");
@@ -1119,6 +1146,7 @@ fn print_session_error(code: &str, message: &str) {
 
 fn print_config_help() {
     eprintln!("herdr config commands:");
+    eprintln!("  herdr config check  validate config.toml and print diagnostics");
     eprintln!("  herdr config reset-keys  back up config.toml and remove custom keybindings");
 }
 
diff --git a/src/cli/spec.rs b/src/cli/spec.rs
index 088bc15e..4c68e3a5 100644
--- a/src/cli/spec.rs
+++ b/src/cli/spec.rs
@@ -88,6 +88,7 @@ fn status_command() -> Command {
 fn config_command() -> Command {
     Command::new("config")
         .about("Manage local configuration")
+        .subcommand(Command::new("check").about("Validate config.toml and print diagnostics"))
         .subcommand(Command::new("reset-keys").about("Reset custom keybindings"))
 }
 
diff --git a/src/config.rs b/src/config.rs
index f3dc9dbb..a2d3f89f 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -67,9 +67,21 @@ impl Config {
             .chain(keybind_diags)
             .chain(self.remote_image_paste_key().err())
             .chain(self.ui.sound.diagnostics())
+            .chain(self.invalid_sidebar_bounds_diagnostic())
             .collect()
     }
 
+    pub(crate) fn invalid_sidebar_bounds_diagnostic(&self) -> Option<String> {
+        validated_sidebar_bounds(self.ui.sidebar_min_width, self.ui.sidebar_max_width)
+            .is_none()
+            .then(|| {
+                format!(
+                    "ui.sidebar_min_width ({}) is greater than sidebar_max_width ({})",
+                    self.ui.sidebar_min_width, self.ui.sidebar_max_width
+                )
+            })
+    }
+
     pub(crate) fn remote_image_paste_key(&self) -> Result<Option<(KeyCode, KeyModifiers)>, String> {
         let raw = self.keys.remote_image_paste.trim();
         if raw.is_empty() {
diff --git a/src/config/io.rs b/src/config/io.rs
index f8c2eb90..6a4e83ce 100644
--- a/src/config/io.rs
+++ b/src/config/io.rs
@@ -154,22 +154,36 @@ pub fn config_path() -> PathBuf {
 }
 
 pub fn config_diagnostic_summary(diagnostics: &[String]) -> Option<String> {
-    const MAX_VISIBLE_DIAGNOSTICS: usize = 4;
-
     if diagnostics.is_empty() {
         return None;
     }
 
-    let mut lines: Vec<String> = diagnostics
+    let target = config_path()
+        .file_name()
+        .and_then(|name| name.to_str())
+        .unwrap_or("config.toml")
+        .to_string();
+    let location = diagnostics
         .iter()
-        .take(MAX_VISIBLE_DIAGNOSTICS)
-        .map(|diagnostic| diagnostic.split_whitespace().collect::<Vec<_>>().join(" "))
-        .collect();
-    let hidden = diagnostics.len().saturating_sub(MAX_VISIBLE_DIAGNOSTICS);
-    if hidden > 0 {
-        lines.push(format!("and {hidden} more config warnings"));
-    }
-    Some(lines.join("\n"))
+        .find_map(|diagnostic| toml_error_location(diagnostic))
+        .map(|(line, column)| format!("{target}:{line}:{column}"))
+        .unwrap_or_else(|| target.to_string());
+
+    Some(format!("{location}; herdr config check"))
+}
+
+fn toml_error_location(diagnostic: &str) -> Option<(usize, usize)> {
+    let marker = "TOML parse error at line ";
+    let start = diagnostic.find(marker)? + marker.len();
+    let rest = &diagnostic[start..];
+    let (line, rest) = rest.split_once(", column ")?;
+    let column = rest
+        .split(|c: char| !c.is_ascii_digit())
+        .next()
+        .unwrap_or_default();
+    let line = line.parse().ok()?;
+    let column = column.parse().ok()?;
+    Some((line, column))
 }
 
 pub fn load_live_config() -> Result<LoadedConfig, Vec<String>> {
@@ -576,7 +590,7 @@ mod tests {
     }
 
     #[test]
-    fn config_diagnostic_summary_keeps_multiple_warnings_visible() {
+    fn config_diagnostic_summary_uses_compact_actionable_banner() {
         let diagnostics = vec![
             "one".to_string(),
             "two".to_string(),
@@ -587,7 +601,33 @@ mod tests {
 
         assert_eq!(
             config_diagnostic_summary(&diagnostics).as_deref(),
-            Some("one\ntwo\nthree\nfour\nand 1 more config warnings")
+            Some("config.toml; herdr config check")
+        );
+    }
+
+    #[test]
+    fn config_diagnostic_summary_includes_toml_error_location() {
+        let diagnostics = vec![
+            "config parse error: TOML parse error at line 33, column 8\n   |\n33 | type = \"popup\"\n   |        ^^^^^^^\nunknown variant `popup`; using defaults"
+                .to_string(),
+        ];
+
+        assert_eq!(
+            config_diagnostic_summary(&diagnostics).as_deref(),
+            Some("config.toml:33:8; herdr config check")
+        );
+    }
+
+    #[test]
+    fn config_diagnostic_summary_finds_location_after_warning() {
+        let diagnostics = vec![
+            "unknown config section [toast]; ignoring section".to_string(),
+            "config parse error: TOML parse error at line 7, column 4".to_string(),
+        ];
+
+        assert_eq!(
+            config_diagnostic_summary(&diagnostics).as_deref(),
+            Some("config.toml:7:4; herdr config check")
         );
     }
 
diff --git a/src/ui.rs b/src/ui.rs
index 129b4e67..dec8d7a9 100644
--- a/src/ui.rs
+++ b/src/ui.rs
@@ -458,7 +458,12 @@ pub fn render_with_runtime_registry(
 fn render_notifications(app: &AppState, frame: &mut Frame, terminal_area: Rect) {
     let has_config_diagnostic = app.config_diagnostic.is_some();
     if let Some(message) = &app.config_diagnostic {
-        render_config_diagnostic(frame, terminal_area, message, &app.palette);
+        let diagnostic_area = if app.view.layout == ViewLayout::Mobile {
+            terminal_area
+        } else {
+            frame.area()
+        };
+        render_config_diagnostic(frame, diagnostic_area, message, &app.palette);
     }
     let mut copy_feedback_offset = u16::from(has_config_diagnostic);
     let mut toast_rect = None;
@@ -681,6 +686,25 @@ mod tests {
     }
 
     #[test]
+    fn mobile_config_diagnostic_keeps_command_visible() {
+        let mut app = crate::app::state::AppState::test_new();
+        app.workspaces = vec![Workspace::test_new("one")];
+        app.active = Some(0);
+        app.selected = 0;
+        app.mode = Mode::Terminal;
+        app.config_diagnostic = Some("config.toml:100:10; herdr config check".into());
+
+        let area = Rect::new(0, 0, 44, 20);
+        compute_view(&mut app, area);
+        let mut terminal = Terminal::new(TestBackend::new(area.width, area.height)).unwrap();
+        terminal.draw(|frame| render(&app, frame)).unwrap();
+        let row = buffer_row_text(terminal.backend().buffer(), area, app.view.terminal_area.y);
+
+        assert!(row.contains("config.toml:100:10"), "{row}");
+        assert!(row.contains("herdr config check"), "{row}");
+    }
+
+    #[test]
     fn desktop_toast_hit_area_uses_full_frame_not_terminal_area() {
         let mut app = crate::app::state::AppState::test_new();
         app.workspaces = vec![Workspace::test_new("one")];
diff --git a/src/ui/status.rs b/src/ui/status.rs
index a49a53f6..ede38b85 100644
--- a/src/ui/status.rs
+++ b/src/ui/status.rs
@@ -179,7 +179,7 @@ pub(super) fn render_config_diagnostic(frame: &mut Frame, area: Rect, message: &
         .take(area.height as usize)
         .enumerate()
     {
-        let text = format!(" config warning: {line} ");
+        let text = format!(" {line} ");
         let width = (text.len() as u16).min(area.width);
         let notif_area = Rect::new(
             area.x + area.width.saturating_sub(width),